Presentation
The performance of an Artificial Intelligence system often depends on the amount of world knowledge available to it. During the last decade, the AI community has witnessed the emergence of a number of highly structured knowledge repositories whose collaborative nature has led to a dramatic increase in the amount of world knowledge that can now be exploited in AI applications. Arguably, the best-known repository of user-contributed knowledge is Wikipedia. Since its inception less than eight years ago, it has become one of the largest and fastest growing on-line sources of encyclopedic knowledge. One of the reasons why Wikipedia is appealing to contributors and users alike is the richness of its embedded structural information: articles are hyperlinked to each other and connected to categories from an ever expanding taxonomy; pervasive language phenomena such as synonymy and polysemy are addressed through redirection and disambiguation pages; entities of the same type are described in a consistent format using infoboxes; related articles are grouped together in series templates.
Many more repositories of user-contributed knowledge exist besides Wikipedia. Collaborative tagging in Delicious and community-driven question answering in Yahoo! Answers and Wiki Answers are only a few examples of knowledge sources that, like Wikipedia, can become a valuable asset for AI researchers. Furthermore, AI methods have the potential to improve these resources, as demonstrated recently by research on personalized tag recommendations, or on matching user questions with previously answered questions.
The goal of this workshop was to foster the research and dissemination of ideas on the mutually beneficial interaction between AI and repositories of user-contributed knowledge. The workshop took place on July 13, 2009, in Pasadena CA, immediately preceding the International Joint Conference on Artificial Intelligence - IJCAI 2009.
This volume contains papers accepted for presentation at the workshop. We issued calls for regular papers, short late-breaking papers, and demos. After careful review by the program committee of the 20 submissions received - 13 regular papers, 6 short papers and 1 demo - 5 regular papers and 3 short papers were accepted for presentation. Consistent with the original aim of the workshop, the accepted papers address a diverse set of problems and resources, although Wikipedia-based systems are still dominant. The accepted papers explore leveraging knowledge induced and patterns learned fromWikipedia and apply them to the web or untagged text collections, using such knowledge for tasks such as information extraction, entity disambiguation, terminology extraction and analysing the structure of social networks. We also learn of useful methods that integrate Wikipedia with structured resources, in particular relational databases.
The members of the program committee provided high quality reviews in a timely fashion, and all submissions have benefited from this expert feedback. For a successful event, having high quality invited speakers is crucial. We were lucky to have two excellent speakers for this year's event. We thank Eugene Agichtein and Timothy Chklovski for their enthusiastic acceptance and presentations.
